It's been a huge week on CBS with big announcements, history-making finales, and more. See what you may have missed this week!

1. David Letterman Announcement After 21 years as the host of "Late Show," David Letterman has announced he will be retiring in 2015. Watch the full announcement.

2. HIMYM Series Finale The highly anticipated How I Met Your Mother series finale was an emotional rollercoaster full of "big moments" packed into the one-hour ending. Check out a recap of the unexpected twists and turns here.

3. Survivor Merge In one of the most anticipated parts of the game, castaways merged into one tribe on Wednesday's episode, plus one of the craziest tribal councils to date led to a shocking blindside. Check out the full episode here.

4. Intelligence Finale Live Tweet Monday night the season finale of Intelligence aired and the cast and crew all joined in to live tweet bonus content from the show! Check the whole recap out here.